Compare historical annual power outage hours (EIA-861), grid islanding risks, and recommended whole-home backup generator and battery sizing across the most vulnerable US electrical grids.
Click any state row to launch its localized pre-hydrated decision calculator.
| State / Interconnection | Avg Outages (hrs/yr) | Grid Risk Level | Primary Vulnerability | Rec. Generator | Rec. Battery | Action |
|---|---|---|---|---|---|---|
AL Alabama SERC / Southern Company | 9.8 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
AK Alaska Railbelt Electric Grid / ASENI | 14.2 hrs | Severe | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
AZ Arizona WECC / APS & SRP | 5.2 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
AR Arkansas MISO / Entergy Arkansas | 12.1 hrs | Severe | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
CA California CAISO (California ISO) | 7.8 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
CO Colorado WECC / Xcel Energy (PSCo) | 6.1 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
CT Connecticut ISO-NE (ISO New England) | 8.5 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
DE Delaware PJM Interconnection | 4.9 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
DC District of Columbia PJM / Pepco | 3.2 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
FL Florida FRCC / FPL & Duke Energy | 15.4 hrs | Severe | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
GA Georgia SERC / Georgia Power | 8.9 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
HI Hawaii HECO (Hawaiian Electric) | 7.1 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
ID Idaho WECC / Idaho Power | 4.1 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
IL Illinois PJM & MISO / ComEd & Ameren | 6.8 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
IN Indiana MISO & PJM / AES & NIPSCO | 7.4 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
IA Iowa MISO / MidAmerican Energy | 5.6 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
KS Kansas SPP (Southwest Power Pool) | 6.4 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
KY Kentucky PJM & MISO / LG&E and KU | 9.2 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
LA Louisiana MISO / Entergy Louisiana | 18.2 hrs | Severe | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
ME Maine ISO-NE / Central Maine Power | 16.5 hrs | Severe | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
MD Maryland PJM / BGE & Pepco | 5.8 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
MA Massachusetts ISO-NE / Eversource & National Grid | 6.2 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
MI Michigan MISO / DTE & Consumers Energy | 14.1 hrs | Severe | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
MN Minnesota MISO / Xcel Energy | 6.9 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
MS Mississippi SERC & MISO / Mississippi Power | 13.5 hrs | Severe | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
MO Missouri MISO & SPP / Ameren Missouri | 8.1 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
MT Montana WECC / NorthWestern Energy | 5.4 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
NE Nebraska SPP / OPPD & NPPD | 5.8 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
NV Nevada WECC / NV Energy | 4.8 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
NH New Hampshire ISO-NE / Eversource NH | 9.4 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
NJ New Jersey PJM / PSE&G and JCP&L | 5.9 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
NM New Mexico WECC & SPP / PNM | 6.2 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
NY New York NYISO / Con Edison & National Grid | 7.2 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
NC North Carolina SERC / Duke Energy Carolinas | 8.4 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
ND North Dakota MISO & SPP / Xcel Energy | 4.9 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
OH Ohio PJM / AEP Ohio & FirstEnergy | 7.6 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
OK Oklahoma SPP / OG&E and PSO | 11.2 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
OR Oregon WECC / PGE & Pacific Power | 6.5 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
PA Pennsylvania PJM / PECO & PPL Electric | 8.2 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
RI Rhode Island ISO-NE / Rhode Island Energy | 6.8 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
SC South Carolina SERC / Dominion & Duke | 9.1 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
SD South Dakota SPP & MISO / Black Hills & Xcel | 5.1 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
TN Tennessee TVA (Tennessee Valley Authority) | 8.7 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
TX Texas ERCOT (Electric Reliability Council) | 19.8 hrs | Severe | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
UT Utah WECC / Rocky Mountain Power | 4.2 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
VT Vermont ISO-NE / Green Mountain Power | 11.5 hrs | High | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
VA Virginia PJM / Dominion Virginia Power | 7.1 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
WA Washington WECC / Puget Sound Energy & Avista | 5.8 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
WV West Virginia PJM / Appalachian Power | 14.8 hrs | Severe | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
WI Wisconsin MISO / We Energies & Alliant | 6.7 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
WY Wyoming WECC / Rocky Mountain Power | 5.1 hrs | Moderate | Severe storms, transmission congestion, and peak climate heating/cooling demand. | 18 kW | 20 kWh | Size Backup |
Data synthesized directly from the U.S. Energy Information Administration (EIA) Form 861 Annual Electric Power Industry Report, the North American Electric Reliability Corporation (NERC) Long-Term Reliability Assessments, and state public utility commissions. Calculations provide engineering and economic estimates and do not substitute for on-site master electrician load calculations.